// flex布局复用
@mixin flex ($hov:space-between, $col:center) {
    display: flex;
    justify-content: $hov;
    align-items: $col;
}

// 背景图片复用
@mixin bgImg ($w:0, $h:0, $img:'', $size:contain) {
    display: inline-block;
    width: $w;
    height: $h;
    background: url($img) no-repeat center;
    background-size: $size;
}